Method of treating copper slag



Patented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

SUKESAKU YOSHIMOTO, OF AKI-GUN, KOCHI-KEN, JAPAN, ASSIGNOR F ONE-THIRDTO TORATARO OKUMURA, OF KOBE-SI-II, I-IYOGO-KEN, JAPAN, AND ONE-THIRD T0SEISHICHIRO NAKAMURA, OF I-IYOGO-KEN, JAPAN.

METHOD OF TREATING COPPER SLAG.

No Drawing. Application filed July 6, 1826, Serial No. 120,866, and inJapan June 2, 1926.

This invention relates to a novel method of treating copper slag andmore particularly to method of making substitutes for tiles, bricks orthe like from copper slag,

and has for its objects to provide a method of converting copper slag ina practical and economical manner into hard and tough articles adaptedfor use as substitutes for tiles, bricks etc., and also to provide amethod for commercially utilizing copper slag which has heretofore beenthrown away, as refuse, at relatively high losses.

Another object of this invention is to obtain from copperslag in asimpleand positive manner the materials adapted for use in architectural,civil or like works, for example, tiles, bricks, pavement materials andso on, which are hard and tough with a metallic luster and sound andtasteful colour.

Other objects and particularities of this invention are fully disclosedin details in the following description.

It has heretofore been well-known that copper slag ejected in copperrefining processes can be coagulated into a block when cooled, but thisblock is extremely fragile and brittle, and is of no practical use as itis. Therefore, it has been necessary in copper refining works to throwaway the blocks of copper slag with a relatively high loss.

According to this invention, copper slag ejected in copper refiningprocesses is taken up in its melted state, and poured into a suitablecasting mould. The mould may be of any suitable material for casting andof any desired or predetermined shape and size adopted in accordancewith the products to be obtained by this invention.

As soon as the slag becomes coagulated in the mold in the most cases itbeing of red heat, it is taken out from the mold and sprinkled upon byany suitable means with a mixture of powders of sulphur, mica and ironand bran, such as rice-bran, and then buried in a mass of straw ashes,and cooled down. As the heat conductivity of straw ashes is very low,the cooling of the block is proceeded so slowly as to prevent naturalcracking of the block by a too rapid cooling.

The above mentioned mixtures of powders may preferably consist of equalparts of the constitutents as specified, in order to obtain the besteffect on the products.

By way of the above mentioned process, I have succeeded in obtaining avery hard and tough mass or article of copper slag, having a metallicluster and sound and a tasteful colour. basis of this invention inobtaining such masses is not clear to the best knowledge of the modernscience, it is still a true fact evolved through repeated series ofexperiments.

Having now particularly described and ascertained the nature and objectsof this invention, I declare that what I claim is:

l. The method of treating copper slag to form commercial bodies,comprising moulding the copper slag in a predetermined size and shape,cooling the block thus formed down to a red heat, applying thereto amixture of powders of sulphur, mica and iron and bran, and annealing,the block thus treated, by slow cooling.

2. The method of treating copper slag to form a hard and tough body,comprising casting said slag in a mold in its molten state, cooling theblock of slag thus formed to red heat, moving it from the mould,sprinkling it with a mixture of equal parts of powders of sulphur, micaand iron and rice-bran, and slowly cooling said block by burying thesame in a mass of straw ashes.

In testimony whereof I have signed my name to this specification.

SUKESAKU YOSHIMOTO.

Although the theoretical

